Milling cutter and method of milling

Abstract

A milling cutter for milling a workpiece comprising a milling head rotatable about its central longitudinal axis. A milling head carries at least one milling insert of a first grade which presents a cutting edge. The milling head carries a wiper insert of a second grade which presents a wiping edge.

What is claimed is: 
     
       1. A method of milling a workpiece comprising the steps of: providing a milling head with a central longitudinal axis, and a forward face;   providing a milling insert, having a cutting edge, being carried by the milling head wherein said milling insert is of a first grade of material having a substrate with a diamond film thereon so as to overlay said cutting edge thereof;   providing a wiper insert, having a wiping edge, being carried by the milling head wherein the wiper insert is made from a second grade of material different from the first grade of material of said milling insert;   rotating the milling head about its central longitudinal axis;   moving the milling head and the workpiece relative to one another so that the milling head engages the workpiece so as to mill the workpiece; and   moving the milling head and the workpiece relative to one another so that the milling head exits the workpiece thereby leaving the milled surface without a burr.   
     
     
       2. The method of claim 1 wherein the wiper insert has a polycrystalline diamond composite portion which defines said wiping edge. 
     
     
       3. The method of claim 1 wherein the workpiece comprises an aluminum-ferrous material composite. 
     
     
       4. A method of milling a workpiece comprising the steps of: providing a milling head with a central longitudinal axis, and a forward face;   providing at least one milling insert, having a cutting edge, being carried by the milling head wherein said milling insert has a first nose radius and wherein said milling insert comprises a first grade of material having a substrate with a thin diamond film thereon so as to overlay said cutting edge;   providing a wiper insert, having a wiping edge, being carried by the milling head wherein the wiper insert has a second nose radius; and wherein said wiper insert is of a second grade of material different from said first grade of material; and wherein said second nose radius is larger than said first nose radius;   rotating the milling head about its central longitudinal axis;   moving the milling head and the workpiece relative to one another so that the milling head engages the workpiece so as to mill the workpiece; and   moving the milling head and the workpiece relative to one another so that the milling head exits the workpiece thereby leaving the milled surface without a burr.   
     
     
       5. The method of claim 4 wherein the wiper insert has a polycrystalline diamond composite portion which defines said wiping edge. 
     
     
       6. The method of claim 4 wherein the workpiece comprises an aluminum-ferrous material composite. 
     
     
       7. The method of claim 4 wherein the workpiece comprises an aluminum-silicon alloy. 
     
     
       8. The method according to claim 1 wherein said diamond film has a thickness of 25 to 30 μm. 
     
     
       9. The method according to claim 2 wherein said diamond film has a thickness of 25 to 30 μm. 
     
     
       10. A method of milling a workpiece comprising the steps of: providing a milling head with a central longitudinal axis, and a forward face;   providing a milling insert, having a cutting edge, being carried by the milling head wherein said milling insert is of a first grade of material having a cemented carbide substrate with a diamond film thereon so as to overlay said cutting edge thereof;   providing a wiper insert, having a wiping edge, being carried by the milling head wherein the wiper insert is made from a second grade of material different from the first grade of material of said milling insert;   wherein said wiper edge projects a greater distance from the forward face of the milling head than does the cutting edge of the milling insert;   rotating the milling head about its central longitudinal axis;   moving the milling head and the workpiece relative to one another so that the milling head engages the workpiece so as to mill the workpiece; and   moving the milling head and the workpiece relative to one another so that the milling head exits the workpiece thereby leaving the milled surface without a burr.   
     
     
       11. The method of claim 10 wherein said second grade is a polycrystalline diamond composite and said wiping edge is sharp. 
     
     
       12. The method of claim 10 wherein said second grade is a ceramic and said wiping edge is a sharp chamfered edge. 
     
     
       13. The method of claim 12 wherein said ceramic comprises a silicon nitride based material. 
     
     
       14. The method of claim 10 wherein said milling insert has a first nose radius and said wiper insert has a second nose radius and said second nose radius is larger than said first nose radius. 
     
     
       15. The method of claim 1 wherein said workpiece comprises an aluminum silicon alloy. 
     
     
       16. The method of claim 4 wherein said workpiece comprises an aluminum silicon alloy. 
     
     
       17. The method of claim 10 wherein said workpiece comprises an aluminum silicon alloy. 
     
     
       18. The method of claim 1 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       19. The method of claim 4 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       20. The method of claim 10 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       21. The method of claim 11 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       22. The method of claim 12 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       23. The method of claim 13 wherein said workpiece comprises an aluminum-ferrous material composite and wherein said milling insert and said wiper insert each engage both said aluminum and said ferrous material forming said aluminum-ferrous material composite, when said the milling head mills the workpiece. 
     
     
       24. The method of claim 11 wherein said workpiece consists essentially of an aluminum silicon alloy. 
     
     
       25. The method of claim 12 wherein said workpiece consists essentially of an aluminum silicon alloy. 
     
     
       26. The method of claim 13 wherein said workpiece consists essentially of an aluminum silicon alloy.